The invention is used in digital and analog circuits, for example flipflops, notably for memories or hyperfrequency oscillators.
The invention is used in particular for integrated circuits realised by means of technologies utilising the semiconductor materials of the group III-V.
The properties of an insulated-gate field effect transistor are known, for example from the publication "New Negative Resistance Regime of Heterostructure Insulated Gate Transistor Operation" by Michael F. SHUR et al in "IEEE Electron Device Letters, Vol. EDL-7, No. 2, February 1986".
This document describes the negative differential drain resistance effect which appears in a field effect transistor comprising an N-type conduction channel with a GaAs-GaAlAs heterostructure and an insulated gate which is constantly biased to a high level.
The structure of this so-called HIGFET transistor comprises a non-intentionally doped GaAs layer having a thickness of 0.5 .mu.m which is provided on a semi-insulating GaAs substrate, followed by a non-intentionally doped GaAlAs layer which serves as a gate insulating layer and on which a gate contact of WSi is realised. Source and drain regions are defined on either side of the gate by localised implantation of Si ions for the N regions or Mg ions for the P-regions. The ohmic contacts on these regions are formed by Au-Ge-Ni metallisations when the regions are of the N-type. The device is insulated by proton implantation. The gate has a length of 1.3 .mu.m and a width of 10 .mu.m.
At a high, fixed value of the gate-source voltage of approximately 3 V, in this device a decrease of the drain-source current occurs when the drain-source voltage changes from 0.8 to 1.25 V. Subsequently, at the same fixed gate-source voltage the drain-source current increases when the drain-source changes varies from 1.25 V to higher values. These variations of the drain-source current as a function of the drain-source voltage at a constant and high gate-source voltage thus lead to the appearance of a negative drain resistance in the saturation regime. This effect is due to a spatial transfer of the carriers in the channel which are collected by the gate. The cited document does not propose any application of this effect.
It is an object of the invention to propose digital or analog circuits which are simpler than the equivalent circuits already known to those skilled in the art.
It is another object of the invention to propose such circuits realised by means of active components which can be realised using technologies which can be readily carried out.
It is another object of the invention to propose such circuits operating at ambient temperature.
Another object of the invention is to propose such circuits whose performance is improved with respect to equivalent circuits known to those skilled in the art.
These objects are achieved by means of a device as described in the preamble, characterized in that it comprises means for applying, across the drain and the source of the insulated-gate field effect transistor, a voltage whose value is in the range of values of the drain-source voltage corresponding to the negative conductance zone.
The advantage of this circuit consists in that it is simple and in that it operates at ambient temperature.